Abstract: An RF modulator according to this invention is constructed so as to allow channel setting without a test pattern generator. Specifically, the RF comprises an A/D converter for digitizing the TV channel setting data, an oscillator control circuit for controlling both the audio carrier oscillation and the RF carrier oscillation on the basis of the channel setting data digitized by the A/D converter, a signal adder for combining the video signal amplitude-modulated at the frequency of the RF carrier oscillation with the audio signal frequency/amplitude-modulated at the frequency of the audio carrier oscillation, channel picking-up means for picking up a portion near the center of each channel in the channel setting data, and a clipper circuit for cutting of the video signal at both ends of each channel setting range that have not been picked up by the channel picking-up means.